Dryer motor switch and actuator

ABSTRACT

In the preferred form, this disclosure relates to a plunger actuated switch assembly for controlling energization of the start and run winding circuits of a dynamoelectric machine having a rotatable output shaft and a centrifugal governor for shifting a collar between a standstill position and a second position when the speed of the output shaft attains a predetermined value. The switch assembly includes a plunger or actuator having an elongated boot portion which rides on the annular periphery of the collar during standstill, the collar holding the switch means in a first position in which it effects energization of both the start and run windings. The switch plunger is spring biased toward a second position in which it effects energization of only the run windings and moves to its second position when the collar is shifted toward its second position.

United States Patent Hancock et al.

[451 Sept. 12, 1972 DRYER MOTOR SWITCH AND ACTUATOR Inventors: James L.Hancock, Fairborn; Joseph A. Bliss, Dayton, both of Ohio Assignee:General Motors Corporation,

Detroit, Mich.

Filed: Sept. 16, 1971 Appl. No.: 181,066

US. Cl. ..310/68 E, zoo/so Int. Cl. ..H02k 11/00 Field of Search..310/68 E; 200/80 R References Cited UNITED STATES PATENTS PrimaryExaminer-D. X. Sliney Attorney-W. E. Finken et a].

[5 7] ABSTRACT In the preferred form, this disclosure relates to aplunger actuated switch assembly for controlling energization ofthe'start and run winding circuits of a dynamoelectric machine having arotatable output shaft and a centrifugal governor for shifting a collarbetween a standstill position and a second position when the speed ofthe output shaft attains a predetermined value. The switch assemblyincludes a plunger or actuator having an elongated boot portion whichrides on the annular periphery of the collar during standstill, thecollar holding the switch means in a first position in which it effectsenergization of both the start and run windings. The switch plunger isspring biased toward a second position in which it effects energizationof only the run windings and moves to its second position when thecollar is shifted toward its second position.

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sum 2 or 2 HEATER INVENTORS Jz zmes 1C Hancock BY Jsep/z f1. 5/235ATTORNEY DRYER MOTOR SWITCH AND ACTUATOR The present invention broadlyrelates to a switch assembly, and more particularly to a plungeractuated switch assembly for use in controlling the start and runwinding circuits of a dynamoelectric machine.

In various dynamoelectric machine or electric motor applications inwhich a high starting torque is extremely important, such as for motorsfor automatic clothes dryers and other appliances, it has been customaryto construct a motor with at least one main excitation or run windingand a start winding. When starting up, both the main and start windingsare energized until the electric motor reaches a predetermined speedwhereupon the start winding is disconnectedfrom the power source.

It is also known to employ a plunger actuated switch assembly forcontrolling energization and de-energization of the start winding and acentrifugal governor mechanism for controlling operation of the switchassembly. The centrifugal governors have included a collar which isshiftable between a first position during standstill and second positionwhen the electric motor has obtained a predetermined speed. The switchassemblies were operatively connected with the shiftable collar viaspring biased levers, flexible levers, or other spring biasing means.The collar served to control movement of the levers or spring biasingmeans, which in turn controlled the movement of the plunger of theswitch assembly.

While the above-noted arrangements have operated satisfactorily, theynevertheless have some drawbacks. The above arrangements requireaccurate calibration of the leaf springs or spring biased levers and/oraccurate positioned of the governor mechanism relative to the levers orspring biasing means if proper operation of the switch assembly was tobe effected. This calibration or accurate positioning is costly, sinceit increases assembly time.

Moreover, it is also desirable to use snap acting overcenter springs formoving the switch contacts of the switch assembly between its positionsand for holding the switch contacts in engagement with their adjacentstationary terminals within a predetermined range of contact pressures.If the contact pressure can be maintained within a desired range for aparticular switch design, the life of the switch is maximized. However,with the prior arrangements and the necessity to accurately calibratethe various spring biased levers etc. the baising pressure exertedagainst the switch plunger often increased the switch contact pressureabove the range of pressures it was designed for. This, in turn, hasresulted in a shorter overall switch life.

The present invention overcomes the above-noted difficulties anddisadvantages by providing a switch assembly having a plunger which isdirectly and slidably engaged by the shiftable collar of the governormechanism so that the governor mechanism does not have to be accuratelypositioned with respect to the plunger of the switch assembly. Moreover,the designed range of contact pressures for the overcenter switch meansis not affected by the position or movement of the collar.

Accordingly, an important object of the present invention is to providea new and improved switch assembly for controlling the start and runwinding circuits of a dynamoelectric machine having a rotatable outputshaft and a centrifugal governor mechanism operable to shift a collarbetween a first position when at standstill and a second position whenthe dynamoelectric machine obtains a predetermined speed, and in whichthe switch assembly includes a plunger or actuator having an elongatedboot portion which extends axially of the shaft and rides on the annularcollar during standstill and which is disengaged from the collar whenthe collar is shifted to its second position to effect de-energizationof the start winding circuit whereby the switch assembly is actuateddirectly by the shiftable collar and the relative position of theannular collar and the boot portion of the plunger of the switchassembly at standstill is not critical.

Another object of the present invention is to provide new and improvedswitch assembly, as defined in the preceding object, and in which theswitch assembly includes an enclosed housing for slidably guiding theplunger for linear movement and a snap acting overcenter spring meansoperatively connected with the plunger and housing for rapidly moving amobile contact into engagement with an associated stationary terminal toenergize only the run windings when the motor reached a predeterminedspeed and for holding the same in engagement with the stationaryterminal at a predetermined pressure force, and wherein the overcenterspring means is so constructed and arranged that it increases thecontact pressure when the dimensions of the mobile contact decrease dueto wear.

Yet another object of the present invention is to provide a new andimproved switch assembly, as defined in the next preceding object, andin which the plunger extends through an opening in the housing andincludes a flange intermediate its ends which engages the inner wall ofthe housing to provide a seal to prevent the entry of foreign materialinto the housing when the plunger has been actuated to energize only therun windings.

The present invention further resides in various novel constructions andarrangement of parts, and further objects, novel characteristic andadvantages of the present invention will be apparent to those skilled inthe art to which it relates and from the following detailed descriptionof the illustrated embodiments thereof made with reference to theaccompanying drawings forming a part of this specification and in whichsimilar reference numerals or characters are employed to designatecorresponding parts throughout the several views, and in which:

FIG. 1 is a fragmentary side elevation view, with portions shown insection, of a dynamoelectric machine embodying the novel switch assemblyof the present invention;

FIG. 2 is an enlarged cross-sectional view of the switch assembly takenapproximately along line 2-2 of FIG. 1;

FIG. 3 is an enlarged sectional view like that shown in FIG. 2, butshowing different parts thereof in different positions;

FIG. 4 is a cross-sectional view taken approximately along line 4-4 ofFIG. 3;

FIG. 5 is a plan view of part of the switch assembly shown in FIG. 2;and

FIG. 6 is a schematic wiring diagram for controlling operation of thedynamoelectric machine shown in FIG. 1.

The present invention provides a novel switch assembly for controllingthe start and run winding circuits of a dynamoelectric machine orelectric motor 12 having a rotatably output shaft 13 and a centrifugal 4governor mechanism 14 for shifting a collar axially of conventionalconstruction and is hereshown as being a single speed, single phase,induction type motor. The motor 12 includes a motor frame 15 forrotatably supporting an induction rotor 16 having an output shaft 13.Surrounding the rotor is a stator 20. As best shown schematically inFIG. 6, the motor includes a main field or run winding 22 and anauxiliary or starter winding 24. These windings are conventionallydisplaced 90 electrical degrees n the stator core and both are energizedduring starting conditions. When the rotor 16 and shaft 13 are broughtup to a predetermined speed, the starter windings 24 are de-energizedand the motor 12 is rotated solely by the main field winding 22.

The switch assembly 10 controls energization and de-energization of therun and start windings 22 and 24, respectively. The switch assembly 10comprises a housing or housing means 30 which is generally rectangularin shape and which is suitably secured to the frame 15 of the electricmotor 12. The housing 30 comprises a pair of complementary halves 31 and32 which are adapted to be secured together via screws 33. The housing30 defines an enclosed chamber 34.

The housing 30 at its left end wall, as viewed in FIG. 3, carries threevertically spaced stationary terminals 40, 41 and 42 and the right endwall of the housing carries three vertically spaced stationary terminals45, 46 and 47. The stationary terminals 40 and 45 are adapted to beelectrically connected in a circuit with an electric heater 48 (see FIG.6) for the dryer (not shown). The terminal 47 is adapted to be connectedin a circuit with the main winding 22 of the electric motor, theterminal 46 is adapted to be connected in the circuit with the main andstart windings 22 and 24 of the electric motor 12 and the terminal 42 isconnected to a suitable ground. The terminal 41 is a junction terminal.The manner in which the terminals are connected in circuit for operatingthe electric motor 12 and the heater 48 of the dryer will be describedin more detail hereinafter.

The switch assembly 10 further includes a pair of snap acting overcentersprings 50 and 51 having one end secured to the terminals 42 and 40 andtheir other or free ends disposed between the terminals 46 and 47 andadjacent the terminal 45, respectively. The overcenter springs 50 and 51carry mobile contacts 52 and 53 at their free ends, respectively. Sinceeach of the overcenter springs 50 and 51 is of an identicalconstruction, only the overcenter spring 50 will be described in detail,and corresponding portions of the spring 51 will be given the samereference numerals as the spring 50.

The snap acting overcenter spring means 50 comprises a one piece springmetal member, preferably made from a beryllium copper alloy material,having a pair of parallel spaced arms 60 and 61 and end portions 62 and63 integrally connecting the adjacent ends of the arms 60 and 61. Theend portion 62 is suitably secured or riveted to the stationary terminal42. The end portion 63 carries the mobile contact 52. The overcenterspring means 50 also includes a pair of bowed leaf spring portions 65and 66 which are respectively integral with the end portions 62 and 63and which extend toward each other. The bowed leaf spring portions 65and 66 are spaced from the parallel arms 60 and 61 and their adjacentends 68 have an arcuate cut out or recess 69.

The overcenter spring means 50 is adapted to be operatively connected toa plunger or actuator 70. The actuator 70 has an intermediate portion 71of rectangular cross section which is slidable received within arectangularly shaped opening 72 in the bottom side housing 30. Theactuator further has an upwardly extending cylindrically shaped or stemportion 73 disposed within the compartment 34 of the housing 30 andwhich is provided with a pair of axially spaced annular recesses 75 and76. The recesses 75 and 76 receive the adjacent free ends 68 of thebowed leaf spring 65 and 66 of the overcenter springs 50 and 51. Theleaf springs 65 and 66 are longer than the distance between their endsintegral with the end portions 62 and 63 and the bottom of the recesses75 and 76, respectively, so that they assume a bowed configuration, asshown in FIGS. 2 and 3, when received within the annular recesses 75 and76 in the stem portion 73 of the plunger 70.

The plunger 70 is adapted to be reciprocated between first and secondpositions as shown in FIGS. 2 and 3, respectively. When the plunger 70is in the position shown in FIG. 2, the mobile contact 53 of theovercenter spring means 51 is disengaged from the terminal 45 whicheffects de-energization of the heater 48 for the dryer and the mobile 52contact of the overcenter spring means 50 is in engagement with theterminal 46 to effect energization of both the start and run windings 24and 22 of the electric motor 12. When the plunger 70 has been moved toits second position, as shown in FIG. 3, the mobile contact 53 of theovercenter spring means 51 engages the terminal 45 to energize theheater 48 of the dryer and the mobile contact 52 of the overcenterspring means 50 engages the terminal 47 to effect energization of onlythe main field winding 22 of the motor 10.

When the plunger 70 is moved between its positions, the overcenterspring means 50 and 51 cause movement of the mobile contacts 52 and 53into and out of engagement with their respective stationary terminalswith a snap action. As can be seen from FIG. 2, when the plunger 70 ismoved downwardly from its FIG. 3, the bowed leaf springs 65 and 66 ofeach of the overcenter spring 50 and 51 are caused to be bowed evenfurther than that shown in FIG. 2 until the ends 68 of the bowed leafsprings 65 and 66 pass beneath the plane of the arms 60 and 61. Whenthis occurs, the bowed leaf springs 65 and 66 will cause the arms 60 and61 and the end portions 63 carrying the mobile contacts 52 and 53 to bemoved upwardly with a snap action until the mobile contacts 52 and 53engage the terminals 47 and 45. Likewise, when the plunger 70 is movedfrom its second position as shown in FIG. 3, toward its first position,as shown in FIG, 2 the bowed leaf springs 65 and 66 of each of theovercenter spring 50 and 51 are caused to bowed even further than thatshown in FIG. 3 until the ends 68 thereof move upwardly past the planeof the arms 60 and 61. When this occurs, the bowed leaf springs 65 and66 will cause the arms 60 and 61 and the end portions 63 to be moveddownwardly with a snap action.

Movement of the plunger 70 between its positions is guided by a guidemeans comprising a rectangularly shaped recess or slot 101 in theforward end wall 102 of the housing 30 and a rectangular flange 104intermediate the ends of the plunger 70. The flange 104 at its rearwardend is received within the recess 101. The plunger 70 is also guided bythe balance of forces acting on the plunger from the bowed leaf springforces 65 and 66 of the overcenter springs 50 and 51. As a result of theflange 104 being received within the recess 101, the rectangular portion71 being slidably received within the rectangular opening 72 and thebowed leaf springs 65 and 66, the plunger 70 is guided for linearmovement up and down relative to the switch housing 30. An advantage ofthis guide arrangement is that it virtually eliminates or minimizesfriction between the actuator and housing 30. It should also be notedthat the flange 104 completely surrounds the opening 72 when the plungeris in its second position, as shown in FIG. 3, and thus, serves toprovide a seal for the enclosed switch chamber 34 to prevent entry offoreign material or lint into the housing 30.

The plunger 70 is biased toward its second position, as shown in FIG. 3,by a biasing means in the form of a bowed leaf spring 106. The leafspring 106 intermediate its ends is suitably secured to the upper end ofthe stem portion 73 of the plunger 70 and at its opposite ends isslidably engaged with the upper side wall 107 of the housing 30. Thebiasing force of the bowed leaf spring 106 is greater than the combinedbiasing force of the bowed leaf springs 65 and 66 of the overcenterspring means 50 and 51 so that the bowed leaf spring 106 will cause theplunger 70 to be moved from its first position, as shown in FIG. 2,towards its second position as shown in FIG. 3, when the plunger 70 isnot held upwardly in its first position.

The plunger 70 is adapted to be moved upwardly from its second position,as shown in FIG. 3, towards its first position, as shown in FIG. 2, whenengaged by an annular collar 110 of the centrifugal governor mechanism14. The centrifugal governor mechanism 44 is carried by the output shaft13 of the electric motor and could be of any suitable or conventionalconstruction. Preferably, it is of the type having an overcenter springmeans 112 for moving the collar 110 with a snap action from a firstposition, as shown by the solid lines in FIG. 1, when the motor 10 isnot operating or at standstill and a second position, as shown by thedotted lines in FIG. 1, when the motor 10 and output shaft 13 haveattained a predetermined speed. Since the centrifugal governor mechanism14 does not per se form a part of the present invention, it will not bedescribed in detail.

The collar 110 is slidably supported on the output shaft 13 and has aradially extending flange 115 at one end provided with an annularperipheral surface 116. The collar 110 functions to engage the plunger70 when the motor is being de-energized to cause the plunger 70 to bemoved from its second position, as

shown in FIG. 3, toward its first position, as shown in FIG. 2. To thisend, the plunger at its lower end has an elongated boot portion 120. Theboot portion has an elongated bottom surface 121 extending axially ofthe output shaft 13 and which is adapted to ride on the annularperipheral surface 116 of the collar when the motor 10 is beingdeenergized or at standstill. The boot portion 120 also has a taperedrearward section 122 which faces towards the governor mechanism 14. Thetaper is linear and progressively increases radially outwardly of theoutput shaft 13 from its forward end towards its rearward end.

Operation of the motor 10 for the clothes dryer will be described withreference to the schematic wiring diagram shown in FIG. 6. The'wiringdiagram includes a manual switch for controlling energization andde-energization of the motor 10, the switch assembly 10, the mainwindings 22 of the motor, start windings 24 of the motor, thermaloverload protector 132, and the electric heater 48 for the dryer (notshown).

When the electric motor 10 is de-energized the collar 110 engages theboot portion 120 of the plunger 70 to hold the same in its firstposition, as shown in FIG. 2. When in its first position, the overcenterspring means 50 and 51 bias the mobile contacts 52 and 53 intoengagement with the stationary terminal 46 and out of engagement withthe stationary terminal 45, respectively. When the operator desires tooperate the dryer he will close the manual switch 130. The closure ofthe switch 130 will complete a circuit from a three wire, AC power lineL, via wire 140, stationary terminal 41, wire 141, thermal overloadprotector 132, wire 143, main winding 22, wire 144, stationary terminal42, wire 146, now closed switch 130, wire 147, to parallel power line LA circuit is also completed from wire 143, start windings 24, wire 148,stationary terminal 46, mobile contact 52, overcenter spring means 50,stationary terminal 42, wire 146, now closed switch 130, wire 147, toparallel power line L The completion of these circuits energizes boththe main and start windings of the electric motor 10.

When the motor 10 reached a predetermined speed, the snap acting,centrifugal governor mechanism 14 will rapidly shift the collar 110 fromits position shown by the solid lines in FIG. 1 to its position shown bythe dotted lines in FIG. 1. Movement of the collar 1 10 to its dottedline position allows the bowed leaf spring 106 to move the plunger 70from its first position as shown in FIG. 2, towards its second position,as shown in FIG. 3. Movement of the plunger 70 towards its secondposition will cause the overcenter springs 50 and 51 to move upwardlywith a snap action until they engage the terminal 47, wire to parallelpower line L to maintain the main windings 22 energized. Movement of themobile contact 53 of the overcenter spring means 51 into engagement withits associated stationary terminal 45 completes a circuit for the heater48 of the dryer. This circuit is from wire 140, stationary terminal 45,

mobile contact 53, overcenter spring means 51, stationary terminal 40,wire 152, heater 48, to parallel power line L} When the operator nolonger desires dryer operation, he will move the manual switch to itsopen position. This breaks the hereinbefore described circuit for themain windings 22 of the motor 10 and causes the motor to bede-energized. As the motor 10 slows down, the snap acting, overcentercentrifugal governor mechanism 14 will cause the collar 110 to berapidly shifted toward the right from its dotted line position towardsits solid line position, as shown in FIG. 1. As the collar 110 isshifted toward the right it will engage the tapered section 122 on theboot portion 120 of the plunger 70 and cause the same to be cammedupwardly and thereafter ride on the underside 121 of the boot portion120. The plunger 70 as it is cammed upwardly is moved from its secondposition towards its first position in which it effects movement of theovercenter spring means 50 and 51 to their position shown in FIG. 2.When the overcenter springs 50 and 51 are in this position, the mobilecontact 52 engages the stationary terminal 46, and the mobile contact 53is disengaged from the stationary terminal 45. This de-energizes theheater 48 of the dryer and positions the switch assembly 10 to initiatestarting operation of the dryer the next time the manual switch 130 ismoved to its closed position.

It should be noted that an important aspect of the present invention isthe provision of the boot portion 120 on the plunger 70. The bootportion 120 allows the plunger 70 of the switch assembly 10 to beactuated directly by the collar 110 and in a manner such that there isno spring force exerted by the centrifugal governor mechanism 14 whichacts in concert with the spring forces of the snap acting switchassembly 10. Hence, the snap acting overcenter springs 50 and 51 can beaccurately designed to have contact pressures within a predeterminedrange. Moreover, the provision of the boot portion 120 eliminates theneed for the collar 110 of the centrifugal governor mechanism 14 to beaccurately positioned with respect to the plunger 70. This is because itmakes no difference whether the collar 110, when in a standstillposition, engages the rearward end of the boot portion 120 of theplunger 70 or engages it further towards it forward end, as long as thetravel of the collar 110 when in its second or run position isdisengaged from the plunger 70 to allow it to be moved downwardly by thebowed leaf spring. Thus, with the above construction and arrangement,the centrifugal governor mechanism 14 can be readily assembled to theoutput shaft 13 of the electric motor 12 without the need to accuratelycalibrate its position relative to the plunger 70 of the switch assembly10. Also, since there is no intermediate actuating means between thecollar 110 and the plunger 70 of the switch assembly 10, calibration ofsuch actuating means has been totally eliminated.

Additionally, it should be noted that the construction and arrangementof the overcenter springs 50 and 51 of the switch assembly 10 is suchthat as the mobile contacts and stationary terminals wear during thelife of the dryer, the contact pressures exerted by the overcentersprings 50 and 51 increases. This is because as the mobile contactsurfaces 52 and 53 wear, the extent of the bow of the leaf springs willbe increased, not decreased, and hence, will cause the mobile contacts52 and 53 to engage their respective stationary terminals with even agreater spring force. This insures that good electrical conductivitybetween the overcenter springs 50 and 51 and the adjacent stationaryterminals takes place throughout the life of the switch assembly 10.

Although the illustrated embodiment thereof has been described in greatdetail, it should be apparent that certain modifications, changes, andadaptations may be made in the illustrated embodiment, and that it isintended to cover all such modifications, changes and adaptations whichcome within the spirit of the present invention.

What is claimed is:

1. In combination, a dynamoelectric machine having first and secondwindings and a rotatable output shaft, a speed responsive governormechanism carried by said machine and including a collar which isshiftable axially relative to said output shaft between a first positionwhen the output shaft is not being rotated and a second position whenthe output shaft reaches a predetermined speed of rotation, and a switchassembly carried by the machine and operatively associated with thecollar for controlling energization and de-energization of saidwindings, said switch assembly including a housing, switch meansincluding a movable switch contact, and actuator supported for linearmovement relative to said housing and radially of said output shaft andoperatively connected with said movable switch contact for moving thelatter, said actuator being movable between a first position in whichsaid switch contact ef fects energization of both of said first andsecond windings and a second position in which the movable switchcontact effects energization of only said first winding, biasing meansfor biasing said actuator toward its second position, said actuatorhaving an elongated boot portion disposed externally of said housing andextending axially of said shaft, said collar when in its first positionhaving its periphery in engagement with said boot portion to hold theactuator in its first position in opposition to the biasing force ofsaid biasing means and being disengageable from the boot portion when inits second position to allow said biasing means to move said actuatortowards its second position.

2. In combination, a dynamoelectric machine having run and startwindings and a rotatable output shaft, a speed responsive governormechanism carried by said output shaft and including a collar which isshiftable axially relative to the output shaft between a first positionwhen the output shaft is not being rotated and a second position whenthe output shaft reaches a predetermined speed, and a switch assemblycarried by the machine and operatively associated with the collar forcontrolling energization and de-energization of said start winding, saidswitch assembly including a housing, switch means including a movableswitch contact, an actuator slidably supported within the housing andlinearly movable relative to the housing and radially of said outputshaft, said actuator being operatively connected with said switchcontact for moving the same, said actuator being movable between a firstposition in which a switch contact effects energization of both saidstart and run windings and a second position in which a switch contacteffects energization of only said run windings, spring means for biasingsaid actuator toward its second position, said actuator having anelongated boot portion disposed externally of said housing and extendingaxially of said output shaft, said collar when in its first positionslidably engaging the boot portion to hold the actuator in its firstposition in opposition to the biasing force of said spring means andbeing disengageable from the boot portion when moved toward its secondposition to allow the spring means to move the actuator toward itssecond position, said boot portion being tapered at its end adjacentsaid collar and said collar being engageable with said tapered sectionupon being returned toward its first position to cam said actuator fromits second position towards its first position and then riding on theunderside of said boot portion when approaching its first position.

3. In combination, a dynamoelectric machine having start and runwindings and a rotatable output shaft, a speed responsive governormechanism carried by said output shaft and including a collar which isshiftable axially relative to said output shaft between a first positionwhen the output shaft is not being rotated and a second position whenthe output reaches a predetermined speed, and a switch assembly carriedby the machine and operatively associated with the collar forcontrolling energization and de-energization of said windings, saidswitch assembly including a housing defining an enclosed chamber havinga side wall portion provided with a non-circular opening therethrough, aplurality of stationary terminals carried by said housing which areadapted to be electrically connected with a power source and the run andstart windings of the dynamoelectric machine, snap acting overcenterspring means having one end secured to one of the stationary terminalsand its other end disposed between two other spaced stationaryterminals, a plastic actuator having a non-circular portion intermediateits ends which is disposed within and shaped complementary to thenon-circular opening in the side wall of the housing and a radiallyextending flange which is engageable with the side wall portion of thehousing around the opening, said actuator also including a stem portiondisposed interiorly of the housing and having a radially extendingrecess therein, said overcenter spring means comprising a pair oflaterally spaced arms integral with each other at their opposite endsand a pair of bowed portions integral with the arms at their ends andwith their other end disposed within the recess of the stem portion ofthe actuator, said actuator being movable between the first position inwhich said overcenter spring means engages the stationary terminal toeffect energization of both the start and run windings of thedynamoelectric machine and a second position in which said overcenterspring means engages another of said stationary terminals to effectenergization of only said run windings of the dynamoelectric machine,spring means engageable with a wall portion of the housing and said stemportion of the actuator for biasing said actuator towards its secondposition, said flange on said actuator engaging the side wall of thehousing when in its second position, said overcenter spring meanscausing said contact to be moved into engagement with the terminals viaa snap action when the actuator ves the bpwed leaf spring portions pastthe p ane 0 t e arms 0 the overcenter spring means, said actuator havingan elongated boot portion extending axially of said shaft and disposedexternally of said housing, said boot portion riding on an annularperipheral surface of said collar and said collar holding the actuatorin its first position in opposition to the biasing force of said springmeans when the latter is in its first position, said boot portionincluding a tapered end adjacent the collar, said collar beingdisengageable from the boot portion when in its second position to allowsaid spring to move said overcenter spring means overcenter and intosnap acting engagement with the other terminal, said collar beingengageable with said tapered section of said boot portion upon beingreturned toward its first position to cam said actuator from its secondposition towards its first position and then riding on the underside ofsaid boot portion when approaching its first position.

1. In combination, a dynamoelectric machine having first and secondwindings and a rotatable output shaft, a speed responsive governormechanism carried by said machine and including a collar which isshiftable axially relative to said output shaft between a first positionwhen the output shaft is not being rotated and a second position whenthe output shaft reaches a predetermined speed of rotation, and a switchassembly carried by the machine and operatively associated with thecollar for controlling energization and de-energization of saidwindings, said switch assembly including a housing, switch meansincluding a movable switch contact, and actuator supported for linearmovement relative to said housing and radially of said output shaft andoperatively connected with said movable switch contact for moving thelatter, said actuator being movable between a first position in whichsaid switch contact effects energization of both of said first andsecond windings and a second position in which the movable switchcontact effects energization of only said first winding, biasing meansfor biasing said actuator toward its second position, said actuatorhaving an elongated boot portion disposed externally of said housing andextending axially of said shaft, said collar when in its first positionhaving its periphery in engagement with said boot portion to hold theactuator in its first position in opposition to the biasing force ofsaid biasing means and being disengageable from the boot portion when inits second position to allow said biasing means to move said actuatortowards its second position.
 2. In combination, a dynamoelectric machinehaving run and start windings and a rotatable output shaft, a speedresponsive governor mechanism carried by said output shaft and includinga collar which is shiftable axially relative to the output shaft betweena first position when the output shaft is not being rotated and a secondposition when the output shaft reaches a predetermined speed, and aswitch assembly carried by the machine and operatively associated withthe collar for controlling energization and de-energization of saidstart winding, said switch assembly including a housing, switch meansincluding a movable switch cOntact, an actuator slidably supportedwithin the housing and linearly movable relative to the housing andradially of said output shaft, said actuator being operatively connectedwith said switch contact for moving the same, said actuator beingmovable between a first position in which a switch contact effectsenergization of both said start and run windings and a second positionin which a switch contact effects energization of only said runwindings, spring means for biasing said actuator toward its secondposition, said actuator having an elongated boot portion disposedexternally of said housing and extending axially of said output shaft,said collar when in its first position slidably engaging the bootportion to hold the actuator in its first position in opposition to thebiasing force of said spring means and being disengageable from the bootportion when moved toward its second position to allow the spring meansto move the actuator toward its second position, said boot portion beingtapered at its end adjacent said collar and said collar being engageablewith said tapered section upon being returned toward its first positionto cam said actuator from its second position towards its first positionand then riding on the underside of said boot portion when approachingits first position.
 3. In combination, a dynamoelectric machine havingstart and run windings and a rotatable output shaft, a speed responsivegovernor mechanism carried by said output shaft and including a collarwhich is shiftable axially relative to said output shaft between a firstposition when the output shaft is not being rotated and a secondposition when the output reaches a predetermined speed, and a switchassembly carried by the machine and operatively associated with thecollar for controlling energization and de-energization of saidwindings, said switch assembly including a housing defining an enclosedchamber having a side wall portion provided with a non-circular openingtherethrough, a plurality of stationary terminals carried by saidhousing which are adapted to be electrically connected with a powersource and the run and start windings of the dynamoelectric machine,snap acting overcenter spring means having one end secured to one of thestationary terminals and its other end disposed between two other spacedstationary terminals, a plastic actuator having a non-circular portionintermediate its ends which is disposed within and shaped complementaryto the non-circular opening in the side wall of the housing and aradially extending flange which is engageable with the side wall portionof the housing around the opening, said actuator also including a stemportion disposed interiorly of the housing and having a radiallyextending recess therein, said overcenter spring means comprising a pairof laterally spaced arms integral with each other at their opposite endsand a pair of bowed portions integral with the arms at their ends andwith their other end disposed within the recess of the stem portion ofthe actuator, said actuator being movable between the first position inwhich said overcenter spring means engages the stationary terminal toeffect energization of both the start and run windings of thedynamoelectric machine and a second position in which said overcenterspring means engages another of said stationary terminals to effectenergization of only said run windings of the dynamoelectric machine,spring means engageable with a wall portion of the housing and said stemportion of the actuator for biasing said actuator towards its secondposition, said flange on said actuator engaging the side wall of thehousing when in its second position, said overcenter spring meanscausing said contact to be moved into engagement with the terminals viaa snap action when the actuator moves the bowed leaf spring portionspast the plane of the arms of the overcenter spring means, said actuatorhaving an elongated boot portion extending axially of said shaft anddisposed externally of said housiNg, said boot portion riding on anannular peripheral surface of said collar and said collar holding theactuator in its first position in opposition to the biasing force ofsaid spring means when the latter is in its first position, said bootportion including a tapered end adjacent the collar, said collar beingdisengageable from the boot portion when in its second position to allowsaid spring to move said overcenter spring means overcenter and intosnap acting engagement with the other terminal, said collar beingengageable with said tapered section of said boot portion upon beingreturned toward its first position to cam said actuator from its secondposition towards its first position and then riding on the underside ofsaid boot portion when approaching its first position.